Improvement in iron buildings and roofs



CHARLES H. PARKER.

Improvement -in Iron Buildings and Roofs.

No. 126,323. PatentedApriI30,1872.

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W MML UNITED STATES PATENT OFFICE.

IMPROVEMENT IN IRON BUILDINGS AND ROOFS.

Specification forming part of Letters Patent No. l26,323, dated April30, 1872.

To whom it may concern:

Be it known that I, CHARLES H. PARKER, of Boston, Suffolk county,Massachusetts, have invented certain new and useful Improvements in theStructure of Iron Buildings and Roofs, of which the following is aspecification:

My invention relates to structures, such as railway depots and likebuildings, the frames of which are composed principally of iron.

The first part of my invention relates to the shoes on which the archesof the roof bear; the object being to obtain such a construction andarrangement of these parts as will allow of compensation for thedifferences in expansion between the arches and their horizontal ties,and will also give increased strength to the shoes.- The next portion ofmy invention relates to the purlins, which extend from end to end of thebuilding or roof, for the purpose of supporting the ribs or arches; andits object is to provide for and take up, between the main arches orribs or in each section or bay, the expansion and contraction of saidparts, so that the strain may be removed which would otherwise come uponthe end walls of the building. The invention also relates to thearrangement of the wind-ties for lateral bracing of the main arches; theobject being to so arrange them as not to interfere with the harmony ofthe contraction and expansion of the parts in each bay or section, andalso to so combine them with intermediate rafters as to form, with saidrafters, a truss to laterally brace the main ribs.

The manner in which my invention is or may be carried into effect willbe understood by reference to the accompanying drawing, in which- Figure1 is a perspective view of so much of a building as is needed toillustrate my invention. Fig. 2 is a detail, showing the construction ofthe purlins. Fig. 3 is a plan view of a part of the roof, representingthe arrangement of wind-ties and intermediate rafters. Fig. 4 is avertical section, transverse to the length of the building, through apart of a column and the end of the rib resting on it.

The bases of each of the metallic main ribs or arches A rest on shoes B,having a convex bearing-surface, w, as sufliciently indicated in thedrawing. The ends of each arch are made correspondingly concave, so asto fit on the bearing-shoes properly. The bearing-surface of the shoe iscurved in the arc of a circle struck from a center some distance belowthe shoe-say the point 0. The main object of this arrangement is tocompensate for the unavoidable difi'erences in expansion between thearch and its horizontal tie C. When the arch ex- ,pands it rises,hanging on the point 0 below the bearing-shoe, whose curvature is struckwith a radius, 0 w. The horizontal movement of the bases of the arch onthe curved bearingsurfaces as will take up the expansion of thetransverse horizontal arch-tie (J. This form of shoe, moreover,possesses not only the advantages stated, but it is also much strongerand not nearly so liable to fracture and break as it would be were itconcave. The purlins D are cantalevered or bracketed out from theinterior opposite sides of each pair of main ribs or arches A to thepoints of contrary flexurep; and between these two points, uniting eachpair of purlins, is an independent girder, E, having a slidingconnection or contraction and expansion joint with each part D.

The parts D E may be made solid, as shown in Figs. 1 and 2; or they maybe made trusslike, as shown at D E, Fig. 2, there being, of course, anexpansion and contraction joint between these parts at p, as abovedescribed.

The wind-ties F of the main arches or ribs are carried to points on thepurlins within the points of contrary flexure p, as shown, so that theharmony of the expansion and contraction is not disturbed. Intermediaterafters G G are arranged between the main arches or ribs. Thoseimmediately adjoining and on each side of each main rib or arch areconnected to the purlins, so that t-hey are thus combined as chords withthe wind-ties to form a truss to laterally'brace the main rib onopposite sides.

The whole structure is so arranged and the parts are so combined thateach bay or section-comprising that portion of the building embracedbetween any two adjoining main ribs or archestakes care of its ownexpansion and contraction independently of that of the others, so thatthere is no accumulation of forces to strain the end walls of thestructurea point of very considerable advantage in long buildings, suchas railroad depots.

Having now described my invention, and the manner in which the same isor may be carried into effect, what I claim, and desire to secure byLetters Patent, is-

1. The combination of the metallic main ribs or arches, their horizontalties, and the convex bearing-shoes supporting the bases of said ribs orarches, substantially as and for the purposes herein described.

2. The combination, with the main ribs or arches, of purlins bracketedor cantalevered out from the interior opposite sides of any twoadjoining ribs to the points of contrary flexure, and independentgirders intermediate between and connected by expansion and contractionjoints with said purlins, substantially as herein shown and described.

3. In combination with the main ribs or nesses.-

CHAS. H. PARKER. Witnesses:

GEO. N. MARCH, WM. A. BLODGETT.

